The present invention relates to an electrical connector for electrically connecting a chip module to a mating circuit board, and particularly to an electrical connector having a positioning member for receiving and positioning solder balls therein and for preventing molten solder from flowing into a housing of the connector.
As technology rapidly develops, electronic components which are constructed with a high degree of precision and stricter requirements are placed upon electrical connectors used with such electronic components. A connector is designed not only to fulfil functional requirements but also to facilitate manufacture thereof. Pertinent conventional connectors are disclosed in U.S. Pat. No. 5,685,725 and Taiwan Patent Application Nos. 81214806, 85209165 and 86102563.
Referring to FIGS. 1 and 2, a conventional electrical connector for electrically connecting a chip module to a mating circuit board comprises a dielectric base 1', a plurality of contacts 3' (amplified in FIG. 1) and a dielectric cover (not labeled). The base 1' comprises a mounting surface 11', a joining surface 10' opposite the mounting surface 11', and a plurality of contact receiving passageways 12' for receiving the corresponding contacts 3' therein. Each contact 3' comprises a contacting portion 33', an engaging portion 31', a resilient portion 32' and a joining portion 30'. The engaging portions 31' are interferentially engaged within the corresponding contact receiving passageways 12'. The resilient portions 32' and the contacting portions 33' are laterally deflected and the contacting portions 33' electrically contact with corresponding terminals of a mating connector. However, since the contacts 3' are inserted into the corresponding passageways 12' from the joining surface 10' of the base 1', gaps are defined between inner side walls of the passageways 12 and the contacts 3'. The gaps allow solder to flow into the passageways 12' thereby decreasing the quality of signal transmission between the connector and the mating circuit board.